Variable delivery and variable pressure vane type pump



Feb. 11, 1964 o. MUELLER 3,120,814

VARIABLE DELIVERY AND VARIABLE PRESSURE VANE TYPE PUMP Filed Oct. 21, 1959 9 Sheets-Sheet 1 E a 24 E INVENTOR.

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VARIABLE DELIVERY AND VARIABLE PRESSURE VANE TYPE PUMP Filed Oct. 21, 1959 9 Sheets-Sheet 3 E E I-EJ IN VEN TOR. Mae/Z2 r 0. MUELLER Feb. 11, 1964 VARIABLE DELIVERY AND VARIABLE PRESSURE VANE TYPE PUMP 9 Sheets-Sheet 4 Filed 001;. 21, 1959 z, w I y V i W INVENTOR. )fzzeZ'ier 0. MUELLER Feb. 11, 1964 VARIABLE DELIVERY AND VARIABLE PRESSURE VANE TYPE PUMP Filed Oct. 21, 1959 9 Sheets-Sheet 5 INVENTOR. Maze/Z97 A )Y VZ/S' NAN Feb. 11, 1964 o. MUELLER 3,120,814

VARIABLE DELIVERY AND VARIABLE PRESSURE VANE TYPE PUMP Filed Oct. 21, 1959 9 Sheets-Sheet s INVENTOR. )Vz/e 77C 71 Feb. 11, 1964 o. MUELLER 3,120,814

VARIABLE DELIVERY AND VARIABLE PRESSURE VANE TYPE PUMP Filed Oct. 21, 1959 9 shee'Ls-sheet 7 0. MUELLER Feb. 11, 1964 VARIABLE DELIVERY AND VARIABLE PRESSURE VANE TYPE PUMP Filed 001;. 21, 1959 9 Sheets-Sheet 8 INVENTOR. Maze/707'.

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Feb. 11, 1964 o. MUELLER 3,120,814

VARIABLE DELIVERY AND VARIABLE PRESSURE VANE 'TYPE PUMP Filed Oct. 21-, 1959 9 Sheets-Sheet 9 LFE I5 '1 INVENTOR. 5Z4 0 Mae/7e 7'.

ag M, 5 I r #7 wav 7 United States Patent a,12s,s14 VARIABLE DELIVERY AND VARIABLE PRESSURE VANE TYPE PUMP Otto Mueller, 13 Byfield Lane, Dearborn, Mich. Filed Oct. 21, 1959, Ser. No. 847,729 17 Claims. (Cl. 103120) This invention relates to pumps, and particularly to a variable delivery and variable pressure pump, and is a continuation-in-part of Serial No. 408,258, filed February 4, 1954, now abandoned.

The present invention pertains to different types of pumps which may be so constructed as to have the amount of fluid delivered and the pressure thereof varied. An example is herein illustrated of a vane type pump which is fully balanced so that the increase of pressure may be substantial without producing undue binding or friction on the pump parts. A sirocco type of pump is also illustrated to show that the principle may be applied to pumps of different designs to produce variable delivery and pressure even though the pump is not balanced. By constructing the pump parts of sufliciently strong material and providing bearings which will withstand heavy loads, the pressure of the fluid may be substantially increased when the volume is reduced. This produces an extremely eflicient type of pump since the power input is balanced with the amount of delivered fluid times the pressure to which the fluid is raised. The pumps are so constructed that the fluid is not churned therein, or first pressurized and then delivered to tank from a pressure relief valve, or by any other means, all of which produces heat and the eizing and destruction of the pump in a very short time.

Thus, when using the proper horsepower for delivering the full fluid capacity of the pump at the rated pressure, the reduction in volume will permit an increase in pressure by the same amount of applied energy. Thus, if the pump has a rating of 50 gallons per minute at 1000 pounds pressure, and the delivery is reduced to ten gallons per minute, the pressure can be raised to 5000 pounds with the same applied energy. It is to be noted that a full intake of fluid occurs at all times and that a portion of this fluid is directed to tank when only the remaining portion is pressurized to deliver a reduced volume of fluid. The fluid which is delivered to tank may be passed through a relief valve set for a low pressure, say of 300 pounds per square inch, to be used as a pilot fluid in a control system. Thus, the pump is capable of efficiently delivering fluid at three pressures, first, the pilot pressure, sec ond, the normal delivery pressure, and third, the high or work-performing pressure. The pump is so constructed with automatic control means that a reduced rate of delivery at increase pressure occurs after the pressure of fluid delivered at normal pressure has increased a predetermined amount when restriction to flow occurs. Thus, it will be seen that the invention pertains to different types of pumps capable of providing variable delivery of fluid at a fixed or increased pressure.

The pump is further constructed so that it may be adjusted to operate when driven in either a clockwise or counterclockwise direction. To accomplish this in the vane type pump, the intake control disk is rotated 90 and the valve and spring control of the compensating mechanism is reversed in the pump assembly. The compensating mechanism operates a bypass control disk from a position in which it may control the lay-passing of fluid with in the pump from zero volume at maximum pump delivery to total volume at zero pump delivery. The fluid passing through this by-pass control disk has substantially no pressure, but through the use of a pressure regulating valve, as pointed out above, a delivery of fluid at lower pressure could be obtained from this discharged fluid. The change in volume delivered by the pump is regulated 3,120,814 Patented Feb. 11, 1964 "ice by angularly adjusting the by-pass disk in relation to the intake disk so that in the vane type pump illustrated the rotor is balanced at all times, having the diametrical pressures always equal. In the gerotor type pump, the intake disk is turned over, a loading spring is changed to one of the opposite hand, and the position of the casting portion for supporting the compression ring is changed Accordingly, the man objects of the invention are: to provide a vane type pump which operates efliicently relative to the input horsepower when varying the delivery of the fluid at a fixed pressure and when increasing the pressure and reducing the volume of the delivered fluid; to provide a pump which is capable of delivering fluid at different volumes and pressure and at different pressures simultaneously; to provide a pump which will deliver fluid at a desired pressure and volume which may be varied, with automatic means for producing the increase in pressure and the decrease in volume after a predetermined amount of fluid has been delivered; to provide a pump which delivers fluid at a variable volume and pressure which is balanced so that it will operate with a minimum of frictionwhen fluid is delivered; to provide a pump having means for changing the position of the outlet port relative to the inlet port so that only a predetermined amount of the delivered fluid will be operated on by the rotor blades while the other portion thereof will be bypassed without being acted upon thereby; to provide inlet and outlet orifices in the side plates of a pump which may be angularly adjusted to permit the pump to operate when driven in either a clockwise or counterclockwise direction, and, in general, to provide a pump which delivers fluid at a variable volume and at reduced volume and increased pressure which is simple in construction, positive in operation and economical of manufacture.

Other objects and features of novelty of the invention will be specifically pointed out or will become apparent when referring, for a better understanding of the invention, to the following description taken in conjunction with the accompanying drawings, wherein:

FIGURE 1 is a sectional view of a pump embodying features of the present invention;

FIG. 2 is a broken sectional view of the structure illustrated in FIG. 1, taken on the line 22 thereof, with parts removed;

FIG. 3 is a sectional view of the structure illustrated in FIG. 1, taken on the line 33 thereof, with parts removed;

FIG. 4 is a sectional view of structure similar to that illustrated in FIG. 3, with the lower passageway deleted and the upper passageway shown in dot and dash lines, with parts removed;

FIG. 5 is a sectional view of the structure illustrated in FIG. 1, taken on the line 5-5 thereof;

FIG. 6 is a broken sectional view of the structure illus trated in FIG. 1, taken on the line 66 thereof;

FIG. 7 is a view in elevaiton of the hub having the plate thereon containing the inlet ports;

FIG. 8 is a view in elevation of the hub having a plate thereon containing the outlet ports when shifted in one position;

FIG. 9 is a view of the structure illustrated in FIG. 8, with the plate shifted a maximum distance in the opposite direction;

FIG. 10 is a view of the structure illustrated in FIG. 7, with the plate containing the inlet ports shifted in the other direction a maximum amount;

FIG. 11 is a view of the structure illustrated in FIG. 8, with the operating parts reversed;

FIG. 12 is a view of the structure illustrated in FIG. 9, with the operating parts reversed;

FIG. 13 is an enlarged sectional view of the structure illustrated in FIG. 4, taken on line 1313 thereof;

FIG. 14 is an enlarged sectional view of the structure illustrated in FIG. 3, taken on the line 1414 thereof;

FIG. 15 is an enlarged broken view of a portion of the structure illustrated in FIG. 1;

FIG. 16 is an end view of a pump of the sirocco type to which the present invention is applied;

FIG. 17 is an enlarged sectional view of the structure illustrated in FIG. 16, taken on the line 1717 thereof;

FIG. 18 is a broken sectional view of the structure illustrated in FIG. 17, taken on the line 1818 thereof;

FIG. 19 is a sectional View of the structure illustrated in FIG. 17, taken on the line 19--1 thereof;

FIG. 20 is a sectional view of the structure illustrated in FIG. 17, taken on the line 202i thereof;

FIG. 21 is a sectional view of the structure illustrated in FIG. 17, taken on the line 2121 thereof;

FIG. 22 is a sectional view of the structure illustrated in FIG. 17, taken on the line 2222 thereof;

FIG. 23 is a broken sectional view of the structure illustrated in FIG. 17, taken on the line 23-23 thereof;

FIG. 24 is a view in elevation of the fluid control plate illustrated in FIG. 22;

FIG. 25 is a sectional view of the structure illustrated in FIG. 24, taken on the line 2525 thereof;

FIG. 26 is a view in elevation of the intake plate illustrated in FIG. 17;

FIG. 27 is a sectional view of the structure illustrated in FIG. 26, taken on the line 27-27 thereof;

FIG. 28 is a broken sectional view of a piston type pump with the structure of the invention applied thereto;

FIG. 29 is a sectional view of the structure of FIG. 28, taken on the line 2-29 thereof;

FIG. 30 is a sectional view of the structure of FIG. 28,

taken on the line 303tl thereof, and

FIG. 31 is a. sectional view of the structure of FIG. 28,

taken on the line 3131 thereof.

Referring to the figures, the housing for the pump embodies a central body casting 11, an intake and drive end casting 12, and a fluid delivery end casting 13. The housing is formed of these three castings which are secured together by suitable bolts 14. The castings are laterally aligned by the projecting annular flanges 15 on the end castings 12 and 13 which extend within the cylindrical face 16 of the center casting 11. One of the apertures 17 which receive the bolts 14 has a bushing sleeve 18 therein which aligns the three castings angularly relative to each other. An O-ring 19 is provided in an annular recess in each end face of the casting 11 by which the three castings are retained in sealed relation to each other. It is to be understood that any number of parts may be employed in the housing rather than the three herein specifically illustrated. In other words, the castings 12 and 13 could be extended to engage with each other and thereby form a two-piece housing.

A rotor 21 is mounted within the assembled housing and embodies a drive shaft portion 22, a body 23, and a rotor 24 having slots 25 in which radially movable vanes 26 are mounted. Between the vanes, passageways 27 and 28 are provided, the passageways 27 being connected by passageways 2? and 31 to a central passageway 32 in the rotor body. The passageways 28 are connected to passageways 33 and 34 to the passageways 32. In this manner, alternate passageways 27 and 28 are connected to the delivery passageway 32 on opposite sides of the rotor 24 so that the passageways will not cut into each other or substantially weaken the structure. At the junction between the passageways 29 and 31 and between the passageways 33 and 34, a ball check valve is mounted, comprising a ball 35 urged into seating position by a spring 36 located about a stem 37 on a closure plug 33 which is sealed within the aperture 39 by an O-ring 41. The plurality of plugs 38 are maintained in their respective apertures 39 by a washer d2 retained in position by a snap ring 43. The stem 37 limits the movement of the ball and the ball check prevents a reverse flow of fluid in the passageways. In view of the fact that the apertures 39 are close to the outer surface of the body 23, strength is provided to the body by sleeves 44 which are shrunk upon the outer body surface. After this assembly, the outer surface is accurately ground to form bearing journals which engage a cylindrical hub 45 of the intake disk 46 and a hub 47 of the by-pass or discharge disk 48. It is to be understood that the body itself may be made larger in diam eter, thereby eliminating the sleeves 44. The disk 48 engages the sleeve 44 and abuts a disk 51 for a purpose which will be described hereafter.

A sleeve 49 is secured to the shaft 22 by a key 51 which prevents the relative rotation between the sleeves and the shaft but which permits a relative axial movement to occur therebetween. The sleeve is supported in a radial bearing 52 and a sealing element 53 seals the shaft to the driving end of the housing. A motor mounting plate 54 is secured to the driving end of the housing by a plurality of screws 55. The disks 46 and 48, with their respective hubs 45 and 47, are preferably made of bronze material to provide bearing surfaces. The disks and hubs are of similar construction, each being provided with a gear sector 56 having an arc of sufficient length to permit rotation of the hubs and disks.

It will be noted in FIG. 1 that the hub 47 difiers from the hub 45 by the provision of an annular extension 142 thereon having a sealing element in the nature of an O-ring 14-3 located in an annular groove in the outer surface thereof, the same as the O-rings 144 disposed in the body of the hubs. A fitting 145 is provided within the aperture 146 of the casting 13 which is sealed thereto by an O-ring 147. Thus, the pressure of the fluid delivered from the passageway 32 in the rotor body will be prevented from acting upon the end of the body 23 thereof and will be limited in its action to the square inch of area of the rotor shaft. To balance this pressure, an annular groove 149 is provided in the face of the plate 46, interconnected by a plurality of slots 150 to a well 151, the fluid in which is at the same pressure as that of the delivered fluid. The area of the annular slot 149 and the slots 150 is one square inch and, having the same pressure of fluid applied therein against the side of the rotor remote from the shaft end, a balance will be maintained on the rotor irrespective of the amount of pressure on the delivered fluid.

A passageway 152 is provided from the delivering passageway 32 in the rotor body which is connected into the passageway 38 for conducting delivered fluid to the shifting mechanism. The delivered fluid also applies pressure to the end of the annular extension 142 of the hub 47 which urges the disks 4%) and the disk 59 against the disk 46 and compression ring 62 to form a seal therewith. Clearance is provided between the rotor body 24 and the disks 46 and 50 when the latter engage the ring 62 to avoid the binding of the rotor between the disks. In this manner, irrespective of the amount of pressure being delivered by the pump, a balance is always main tained on the rotating parts which are free to operate with a minimum of friction. An annular passageway 153 is provided about the hub 47 connected by a passageway 154 to the area 155 at the left-hand end of the body 23 and also by a passageway 155 to the return passageway 121 so that the fluid will be drained from the end of the body 23 to prevent any pressure from being built up therein, in the same manner as the passageway 85 returns fluid to the low pressure side of the system when fluid is collected within the interior 58 of the casting 12. The casting 12 has an inlet port 63 communicating with the hollow interior 5% thereof, while the casting 13 has an outlet port 65 for the return of excess fluid not under compression in the hollow interior 57 thereof, to tank.

As pointed out 'hereinabove, the pump may be operated in either a clockwise or counterclockwise direction. Referring to FIG. 5, the disk 46 has inlet ports 66 and 67 which are diametrically disposed. In the figure, the ports 66 and 67 are shown on the suction side of the compression ring when the rotor is to be driven in a counterclockwise direction. When the ports 66 and 67 are shifted 90 into the position illustrated in FIG. 10, then such ports are located on the suction side of the ring when the rotor is driven in a clockwise direction. In this particular situation, the shifting of the ports occurs through an arc of 90, which is accomplished by the use of a gear 68 having teeth engaging the teeth of the sector 56. The gear is secured by a key 69 to a shaft 71 which is sealed in an aperture 72 of the casting 12 by an O-ring 73. The gear abuts a shoulder 74 on the shaft 71 and the gear and shaft are locked in adjusted position by a nut 75 hearing against a washer 76. The forward end of the shaft 71 has a hexagonal head 77 or other means by which it may be rotatably adjusted. The periphery of the disk 46 is cut away at 78 to form a recess for receiving a key 79 which limits the travel of the disk arcuately when adjusted by the gear 68. When the disk is adjusted to a position as illustrated in FIG. 7, the rotor is to be driven in a counterclockwise direction. When the disk is shifted in a counterclockwise direction to have the end 81 of the recessed portion 78 strike the key 79, then the ports are in position to have the rotor drive in a clockwise direction, as illustrated in FIG. 10. The key 79 is retained in position in recesses 32 in the annular flanges 15 of the castings 12 and 13 and in the keyway 83 in the central casting ll. Similarly, the key is effective for retaining the compression ring 62 in position, being erttended within a slot 84 contained therein. The fluid being pumped will lubricate the hubs 45 and 47 with the bearing surfaces of the sleeves 44 and any fluid under pressure which may pass into the well 58 and about the bearings $2 and seal 53 is relieved through an orifice 85 connected to the intake port 63.

After the disk 46 is set into the dotted or dot and dash line positions, as illustrated in FIG. or in FIGS. 7 or 10, to have the shaft 22 driven in a clockwise or counterclockwise direction, the proper rotation of the shaft will cause fluid from the intake port 63 to pass through the intake ports 66 and 67 of the disk 46 into the area b tween the vanes, the rotor, and the internal generated surface of the compression ring 62. This fluid will be carried forwardly on the rising side of the generated surface without compression and on the falling side of the surface will compress the fluid and force it through the orifices 27 and 2% and into and from the passageway 32. Such a delivery of fluid will occur in either direction of rotation of the shaft 22 depending upon the adjustment of the ports of the disk 46. in this manner, a maximum delivery of fluid will be obtained from the outlet passageway 59.

By adjusting the disk 4% and the ports 36 and 87 thereof relative to the ports es and 67 of the disk 46, the amount of delivered fluid under pressure may be varied. When the disk 43 has the ports 86 and 37 in alignment on opposite sides of the rotor 24 with the intake ports 66 and at, as illustrated in FIGS. 7 and 9, all of the fluid will be delivered to the compression side of the pump and will be pressurized and delivered from the port 59, thereby delivering the maximum capacity of the pump. When the disk 48 has been rotated a maximum amount to have the ports 36 and 37 disposed in substantially 90 offset relation to the ports 66 and 6'7, as illustrated in FIGS. 7 and 8, then the fluid delivered from the ports 6% and 67 will be returned through the ports 85 and 87 to tank through the port 65 of the housing without being pressurized. In a shifted position of the ports 86 and 87 between the positions illustrated in FIGS. 8 and 9, a portion of the fluid will be returned to tank while another portion thereof will be pressurized and delivered through the port 5'3, the amount of which is controlled by the location of the ports 36 and 87. Such location may be accomplished manually by any means for rotating the hub 47 and disk 43. The same arrangement for clockwise rotation of the shaft 22 is illustrated in FIGS. 10, 11 and 12. A plurality of apertures 89 are provided through the disk 5%? for controlling the flow of fluid from the discharge ports 86 and 87 to prevent it from moving from an intake area in the rotor 24 which is not to be directed to tank. The fluid can only pass from the ports 86 and 87 through the uncovered apertures 80, to thereby positively control the areas from which the fluid may be discharged.

Preferably, however, automatic compensating means are provided which may be preset to deliver the desired amount of fluid from zero to maximum after the initial delivery of full capacity under normal pressure. The arrangement is such that in initiating the pump operation the set delivery of fluid will occur to perform operations at normally delivered pressure, after which, when the pressure builds up on the fluid, the mechanism will be operated to shift the disk 48, to thereby reduce the amount of fluid being delivered at an increased holding pressure or at a substantially higher pressure.

The well 57 is connected by a passageway 88 to a passageway 89 which is connected by passageways 91 to each end of a bore 92 of the casting 13. When. the rotor is to be driven in the counterclockwise direction, as shown in FIG. d, the left-hand end of the bore 92 contains a plug 93 which is threaded therein and sealed thereto by an O-ring 9 A stem 95 has a threaded end 96 threaded into the end of the plug 93, with its forward end containing a washer fid which is pressed upon the reduced end portion 97 against the shoulder formed thereby. The washer acts upon a spring i3, the opposite end of which engages a shiftable control valve 99 which is located in the opposite end of the bore and urged by the spring against a plug ltli which is threaded in the end of the bore and sealed therein by an O-ring 102. The passageway '3 at L16 right-hand end of the bore, as illustrated in PEG. 6, enters a plurality of passageways m3 into a cavity 219 i within the bore. A hollow stem on the end of the valve 99 extends within the plug Mil into the cavity 194. A passageway tee in the stem 195 is connected by a plurality of passageways 1&7 to an annular recess ass of the bore 22 through passageway 199 into an annular recess 111 of a bore 112. i

As illustrated in FIG. 5, the bore 112 contains a piston 113 having on one side thereof rack teeth 114 which mesh with the teeth of a gear 115 which is disposed in driving relation to a gear 115 in mesh with the teeth of the sector 56 of the hub 47. The gears 115 and lie are journaled upon the extending portion 117 of the shaft 71, having a reduced end portion 118 journalcd in an aperture 119 in the casting 13. A passageway 121 is provided through the shaft portion 117 having outlet passageways 122 which communicate with the hollow interior 64 of the casting on the intake side thereof. The fluid delivered to the recess 111 shifts the piston 113 to the left to the position illustrated in FIG. 5. As the pressure builds up on the fluid, the pressure in the cavity 1(34 acting on the stem 195 will overcome the pressure of the spring 93 and the valve 95% will shift to the left, connecting the ports 1&7 with the annular recess 123. The fluid delivered to the recess 123 passes through passageways 124, 121) and 125 to the annular recess 12% on the lefthand end of the piston 113 to cause the piston to shift to the right. The fluid ahead of the piston 113 is conducted through the passageway 109, the annular recess 10%, through the passageways 127, through the passageway 12% of the stem 12W of the valve 99 into the central portion of the bore 92. An annular recess 131 in the wall of the bore 92 is connected by a passageway 132 to the aperture 119 in which the end of the extending portion 117 of the shaft 71 is located so that the fluid from the central portion of the bore can pass through the passage i132, the passageways 121 and 122, to the intake side of the recess 64 of the housing. Each end of the bore 112 is provided with a plug 133 which is threaded therein and scaled by an Q-ring A stern 135 extends forwardly of the plug and is supported for adjustment therein by a threaded end. 136 which is threaded into the end of the plug. Protective caps 341 are threaded to the plugs 133 to protect the threads 1 .36 of the stem 135. A lock not 137 secures the stern in position after adjustment and an O-ring seals the stem to the inner bore of the plug i153. The stems are adjusted to limit the travel of the piston H3 in either direction, thereby controlling the travel rotation of the hub 47 and the position of the ports as and 557 of the plates 48, to thereby control the amount of fluid being delivered by the pump to provide the desired delivery at normal pressure and a reduced delivery at a higher pres sure. When operating the pump, fluid at a normal pressure will be delivered until certain functions, such as the operation of clamps and slides, required of the normal pressure fluid will be performed, after which, upon the increase of pressure of the delivered fluid resulting therefrom, the piston 113 will automatically shift, advancing the ports 86 and 8'7 an amount limited by the stem 1% which controls the reduced rate of delivery of fluid, the pressure on which is substantially increased to perform further work, such as a punching or riveting operation. The higher pressure will be delivered to the system until the cycle of operation is complete and a by-pass valve opens to drop the pressure therein. When the pressure is reduced to substantially the normal or initial pressure delivered by the pump, the spring 98 will shift the valve 99 to the right to the position illustrated in MG. 6.

The above description applies to the pump when the rotor is operating in a counterclockwise direction. v/Vhfiil it is desired to rotate the pump in a clockwise direction, the nut 75 on the shaft '71 is loosened and the head ?"7 of the shaft adjusted to shift the ports 66 67 from dotted position illustrated in PEG. 5 to the dot and dash position thereof. These positions are illustrated in FIGS. 7 and 10 respectively. The plug 93 and stei 95 and the plug 101 and valve W are removed from the ends of the bore 92 and are interchanged and inserted in the opposite ends so that the plug 101 and valve 99 will be on the left-hand end of the bore 92, as illustrated in FIG. 6, and the plug 93 and stem 95 will be on the righ hand end thereof. As illustrated in F163. 10, 11 and 12, the position of the piston 113 is reversed from that illustrated in FIGS. 7, 8 and 9 to shift the disks 48 in the opposite direction due to the shifted position or the intake ports 66 and 67 and the opposite direction of rotation of the rotor. The ports 86 and 87 will the same relationship to the shifted ports on and 67 when the pump is driven in a clockwise direction for delivering maximum or reduced volume of fluid at normal or higher pressure, the same as described above when the pump is driven counterclockwise.

T permit the same automatic operation of the plates 48 when the motor is driven in a clockwise direction, reversing passageways 110 and 123i are employed which are illustrated more specifically in FIGS. 3 and 4 and in FIGS. 13 and 14. It will be noted that the section of FIG. 3 passes through the port lid, while the section of FIG. 4 passes below the port 124 The passageway 1&9 communicates with the passageway Silt while a similar passageway 125 at the opposite end or the bores communicates with the passageway A passageway 124 communicates with the passageway iii? and a similar passageway 124 communicates with the passageway at the opposite end of the bores. This is also shown in FIGS. 13 and 14, the broken portions being offset sections at opposite ends of the bores. As pointed out hereinabove, when the fluid under pressure passes into the annular passageway 1%, it communicates with the passageway Elli) through passageway 3 which communicates with the annular groove Mill in the bore 1E2. This causes the piston 113 to shift to the opposite end of the bore and thereby rotate the plate 43 to regulate the maximum amount of fluid being delivered. As the pressure increases after certain work is performed at normal pressure, such as operating clamps, slides and the like, the pressure of fluid will increase, shifting the valve 9% and directing the fluid under pressure into the annular groove 123. The annular groove $.23 delivers pressure from the passageway 124 to the passageway from which it is directed from the passageway to the annular groove 126 at the opposite end of the bore 112 to cause the piston 113 to return to its initial position, thereby reducing the amount of fluid delivered and permitting the useful horsepower of the pump to increase the pressure of the reduced amount of delivered fluid. This increase in pressure will complete the cycle of operation by performing a punching, riveting or similar operation, after which the fluid of the system is by-passed to tank and the pressure in the pump drops, permitting the spring 98 to return the piston 99 to its initial position ready to perform a new cycle of operation upon the changing of the workpiece. Through the use of the passageways HS and 120, it will be readily seen that by reversing the position of the elements in the bores 92 and 112 the pump will operate in the opposite direction and the flow of fluid in passageways 110 and IE2 will be such that the same sequence in shifting of the piston 113 and the valve 99 will take place.

By employing a pressure regulated valve 142 at the outlet 65, the fluid to be delivered to tank is maintained at a pressure substantially lower than normal pressure and can be used as pilot pressure for operating control valves of a system. Thus, the pump is able to deliver fluid at pilot pressure, at normal pressure, and at a high working pressure. These pressures may vary substantially from each other but may be, for example. in the nature of 300 lbs. for the pilot pressure, 1000 lbs. for the normal pressure, and 5,000 lbs. for the high pressure.

While the pump operates satisfactorily with the disk 48 directly engaging the rotor 24, it will be noted in FIG. 1 that a disk 5% is disposed between the left-hand face of the rotor 24, compression ring 62 and the discharge disk 4-8. The disk has a slot therein for receiving the key 83 which positions the disk and retains it stationary relative to the disk 4-8 which is rotatable 90 relative thereto. The disk Ed has diametrically opposite areas 162 and 163 containing a plurality of rows of apertures 8d through which the unpressurized fluid passes to the elongated outlet ports 86 and 87 to tank. When the disk 48 is rotated from the position illustrated in FIG. 9 toward the position of PEG. 8, the apertures 3d will be progressively uncovered and more of the intake fluid will pass to tank and a reduced amount will be pressurized. The apertures 8t} c0nfine the discharge of fluid from the area uncovered and prevent duainage from areas not to be affected. The communication of the apertures 3% with the outlet 87 is illustrated in FIG. 15 along with the teeth as by which the disk 43 is rotatably adjusted.

Referring to FIGS. 16 to 27, another form of the invention is illustrated to show that the structure of the invention may be applied to other types of pumps. The pump is known in the trade as the SiIOCCO pump and comprises a rotor 171 operating within a compression ring 172. Within the recesses 13 of the ring, the projecting teeth 174, of the rotor draw in the fluid on one part of the ring and compress the fluid on another part thereof. The ring and rotor are of conventional form well known in the art and the actual shape of the teeth and recesses is not described herein in detail. The pump has a housing which is cast in three parts, the rotor and ring enclosing the central casting portion 175 and intake and exhaust casting portions 7.76 and 177, respectively, the adjacent ends of which extend over and are sealed to the central portion 175. The intake portion 176 has an intake opening 17 communicating with an annular passageway 173 by which the fluid is directed against the face of a plate 179 containing an intake aperture 181, shown more specifically in H6. 26. The aperture is illustrated by a solid line when the pump is operating in one direction and in broken line when the plate is turned over about a horizontal line to permit the pump to operate in the opposite direction.

A shaft 182 extends through the three casting portions 175, 176 and 177 and is supported at the driven end by a floating type of roller bearing 1S3 disposed within an aperture 1.3 4 at the end of the casting portion 176. A seal 135 is secured Within an aperture in the casting portion in engagement with the shaft. A securing plate 1556 contains a sealing element 187 which further seals the shaft 132 at the driven end thereof when the plate is secured by a plurality of screws 188 to the front face of the casting portion 176. An annular rib 139 on the shaft 182 engages an annular bushing 191 which abuts the rotor 171. The rotor has a central splined aperture 192 which engages the splines 193 on the shaft which is retained against endwise movement by the confinement of the rotor between the plates 179 and 209.

The shaft has a barrel 194 disposed thereon secured against rotation relative to the shaft by a pin 195 which is inserted in position through an aperture 199. The barrel rotates with the rotor and discharge apertures 1% are aligned with apertures 197 in the barrel in which a spring 1% urges a plunger 19% against a ball 2'01 which engages a seat 262 at the mouth of the discharge apertures 196. The discharge apertures 196 are located between the teeth 174 of the rotor and since there are eight teeth illustrated, with eight areas therebetween, eight of the balls are provided, urged against the seats 2 of the apertures. The apertures 196 are joined to the recesses between eaoh pair of teeth 174' by a pair of apertures 203. When the balls are unseated one after the other, the flu-id in the recess between the teeth 174 is pressurized and forced past the balls and recesses 204 located in the outer peripheral face of the barrel. Any drainage of oil under pressure to within the recess 197 will pass therefrom through the aperture 2% to the drain discharge port. A was-her 266 forces the barrel 1% against the rotor 171 through the pressure produced by a nut 267 screwed upon the thread 268 of the shaft.

A washerlike plate 212-9 is mounted against the left-hand face of the rotor 171, the ring 172 and the central casting portion 175. The casting portion 177 abuts the outer portion of the ring and the casting portions 175, 176 and 177 are secured together by a plurality of screws 211 which extend therethrough and through the disks 179 and 269, all of which are retained in fixed relation to each other. A pair of G-rings 212 is disposed in slots in the peripheral wall of the central casting portion 175 engaging the inner surface of the overhanging sections of the casting portions 176 and 177, and O-rings 213 and 21 i seal the faces of the central casting portion 175 and the disks 179 and 2419. l

A disk 215 is mounted within the casting portion 77 and disposed in abutting relation to the disk 26?. The disk carries a hub 216 having sealing rings 217 on its outer face which engage an internal annular surface 213 within the casting portion 177. The hub 216 has a reduced annular extension 21) provided with a plurality of teeth 221 which are in engagement with t e teeth 222 of a cylindrical rack 223 which will be described more fully hereinafter. By means of the rack teeth 222 and teeth 221, the hub 216 is rotatably adjusted for changing the position of the disk 215 relative to the disk 2&9. The disk 215 and hub 216 are retained against endwise movement by a shoulder 22-4 on the interior surface of the casting portion 177.

The left-hand end of the casting portion 177 contains a cylindrical recess 2255 in which a floating type of roller bearing 226 is mounted for supporting the left-hand end of a shaft 182. A lock type nut 227, secured upon the thread 228 of the shaft, secures the inner race of the bearing to the shaft and the shaft is permitted to move endwise in the floating type of bearings 183 and 226. An end cap 229 is secured to the left-hand end of the casting portion 177 by a plurality of screws 231, sealed thereto by an O-ring 232.

The hub 216 has an annular boss 233- for supporting one end of a flat coil spring 234, the end 235 being secured in an aperture 236 through the boss. The opposite end of the spring is secured to an aperture 237 in an inwardly directed annular flange 238 ina ring worm gear 239, the outer surface of which is in rotatable engagement with the inner surface of a cylindrical aperture 241 in the casting portion 177. The worm wheel teeth 242 are engaged by a thread 243' of a worm 244 which is mounted in a boss 24-5 of the casting portion 177, as illustrated in FIG. 19. The worm has an enlarged end 246 containing an annular slot 247 in which an O-ring 248 is placed for engaging the inner cylindrical surface 249 in the boss. A large head 251 containing a hexagonal aperture 256 is provided on the end 246 on the head of the worm 244 in engagement with a washer 252 for securing the lead screw against shifting to the left. A nut 253 threaded on the opposite end of the worm against a washer 254 prevents the lead screw from shifting to the right. The left-hand end of the worm has an annular slot 255 therein for receiving an O-ring 25s which engages the surface 249 to thereby seal the left-hand end of the worm with the wall of the cylindrical aperture 257. A knob 258 is secured by a pin 25) to the outer end of the worm 244, permitting it to be manually rotated to thereby rotate the ring worm gear 239 to tension the spring 234, for a purpose which will be explained hereinafter.

The disk 2%, as illustrated more specifically in FIGS. 22 and 25, is provided with an area 2&1 containing a plurality of rows of apertures 262 which are disposed adjacent to the reduced volume areas 263, 264 and 265 of the pump. if the apertures are not covered by the face of the disk 215, the fluid normally being compressed in the areas will pass from the apertures 262 through the disk 215 into the area 266 within the casting portion 177. The disk as illustrated more specifically in 21, has a semi-cylindrical recess 267 containing a plurality of apertures 268 which communicates with the area 266. When the recess 26? of the disk 215 does not extend over the area 251 containing the apertures 262, full volume of intake fluid will be pressurized in the reduced area zones 263, 264 and 255 and full volume of pressurized fluid will be delivered from the pump. If, however, the recess of the disk 215 extends over the group of the apertures 262 within the area 261, the full intake of fluid will pass through the apertures 252 into the recess 267 out through the apertures 2-68 and into the area 266 which communicates with a discharge port 269 illustrated more specifically in FIG. 20. When the recsss 267 covers a portion only of the area 261, some of the full intake of fluid will pass to the discharge aperture 269 and the remainder will be pressurized and passed through the apertures 2:93 into the apertures 19%, past the balls 2551, past the barrel 1%, through apertures 271 into a pressure area 272 which communicates with a pressure delivery port 273, as illustrated in FIGS. 17 and 20. It will be noted from FIG. 23 that the securing screws 211 are equally spaced, thereby permitting the casting portion 176 to be positioned through 369', there by locating the intake port l7fi at intervals of 45 which may be reduced by addiru additional equally spaced apertures and screws 211 to the assembly.

A recess 27% in the face of the disk 215 has an arcuate portion 274 of greater radius than the connecting arcuate portion 275 which is of less radius. The portion 27d extends beyond a plurality of cylindrical recesses 277 in the area 276 in the disk 299 disposed diametrically opposite to the area 261 containing the apertures 262. The arcuate section 275 of less radius is advanced along the area 273 between the two rows of recesses 277 in communication therewith. The pressure of fluid in the recesses 277 balances the pressure in the apertures 262 which are covered by the face of the disk 215. As more and more of the apertures 262 are uncovered, fewer and fewer of the recesses 2 77 are provided with fluid so as to thereby produce a balance on opposite sides of the disk 299 as the disk 215 is adjusted relative thereto. An aperture 279 extends into the disk 269 communicating the pressure area at the central aperture of the disk with the recess 27% in the face thereof. The spring 234, the fluid which is by'passed through the aperture 269, and the high pressure fluid in the area 272 urge the disk 215 against the face of the disk 2439 with increasing pres sure as the pressure of the fluid is increased. It is to be understood that the fluid lay-passed to tank from the discharge port 269 may be passed through a pressure regulating valve which will increase the pressure on the disk 215 and supply fluid at a pressure lower than the normal pump pressure. As pointed out hereinabove, the low pressure fluid may be employed for operating auxiliary elements, particularly those of a fluid control system requiring a pilot pressure.

The spring 234- which initially applies pressure to the disk 215 retains it in partially sea-led relation to the disk 269 at all times. The winding of the spring by the turning of the knob 253 produces a tension which must be overcome when the hub 216 is rotated. For rotating the hub by pressure means, the cylindrical rack 223 has its teeth 222, engaged with the teeth 221 at the end of the hub 216. The body of the cylindrical rack has one end larger in diameter than the other, both ends being reciprocably mounted within a pair of sleeves 281 and 282 of different internal diameters secured by the threads 28% in an aperture 284 at the ends of a boss 23% on the casting portion 177, sealed therein by O-rings 235. The cylindrical rack is illustrated as having been shifted to the right in position to be moved toward the left when the pressure fluid in the area 272; engages the annular shoulder 286 on the body thereof. The sleeves 281 and 282 have threaded elements sealed therein by an Using 2% disposed in the annular slot in the body. The inner ends of the elements 292 have a head 294 thereon with a hexagonal stem 2% provided in extension thereof. The hexagonal stern projects into a hexagonal aperture 2% of a stud 297 which is screwed into a threaded aperture 29% within the ends of the cylindrical rack element 223. The stud 25*7 strikes the heads 29-; when the cylindrical rack is moved to the left and right, thereby limiting the amount the plate 215 is angularly adjusted and the maximum and minimum amount of pressurized fluid which the pump can deliver. Any fluid collected in the ends of the sleeves 281 and 282 interfering with the operation of the cylindrical rack 223 will be forced into the by-pass area 265 from the passageways 291, annular recesses 299 and passageways 2% illustrated in FIG. 23. The elements 292 are turned by a wrench inserted in the hexagonal apertures Bill in the ends thereof and locked in adjusted position by the nuts 302.

When the cylindrical rack 22-3 is advanced to the left, as illustrated in FIG. 20, the ring worm wheel 239 is rotated to wind up the spring 234 to thereby require an increased pressure of fluid acting on the shoulder 2% to produce the movement of the rack and change the position of the disk 215. When normal resistance to the flow of fluid is present, the full capacity of the pump will be delivered. When the resistance to flow is increased, the resulting increased pressure shifts the cylindrical rack 223 to the left, rotating the disk 215 and reducing the :amount of delivered fluid While increasing its pressure until the resistance to flow is overcome or the capacity of the pump has been reached. The rotation of the disk 215 by the rack 223 Winds the spring 234 beyond that et by the Worm 2 54 to thereby require an increase of pressure to further shift the rack 223 which thereby causes a further decrease in the delivery of the fluid and an increase in the pressure thereof. A constant delivery below maximum rate can be obtained if the spring 234 is omitted and a connection is made between the worm ring 239 and the hub 216. Such a construction will permit the adjustment of the disk 215 by the rotation of the worm 244 to obtain a reduced supply of pressurized fluid. When the worm ring 239 is not connected to the hub 216, a lever may be connected thereto to produce the adjustment of the disk 215. The lever may be connected to an operated device which will shift the disk when it reaches a selected point in its travel to by-pass the fluid. If pressure is required to maintain the device in position, the disk 215 :will be shifted back toward its initial position, closing off a portion of the by-p ass area to cause a pressure to be applied to the device to return it to the desired position. Separate passageways may be employed to supply fluid to the shoulder 2% of the cylindrical rack 223 to control its movement irrespective of the pump delivery or pressure. When the direction of operation of the pump is changed, the sleeves 231 and 282, along with the cylindrical rack, are reversed end for end in the boss 233 of the casting portion 177.

The differential cylindrical rack 223 permits the spring 234 to shift the rack to the right to its initial position when the pressure is removed from the differential area 286 thereof. By adjusting the hexagonal stems 2-95 in rotation, the degree of movement of the cylindrical rack 223 to the left and right is thereby controlled. The limitation of the rack when shifted to the left controls the maximum output of the pump while the stop positioning of the cylindrical rack to the left, as viewed in the figure, limits the minimum amount of fluid which can be delivered. Thus, if the pump is rated at 22%. gallons per minute, the adjustment of the right-hand stop sleeve could limit the maximum delivery of the pump to eighteen gallons, and by the adjustment of the left-hand stop sleeve the minimum number of gallons delivered could be small, say zero to four or five gallons. The pressure of the fluid to be delivered is controlled by the tension of the spring 234 which must be overcome by the pressure of the fluid in the area 272 acting upon the shoulder 286 to shift the cylindrical rack to the left. It is to be understood that the casting sections 176 and 1'77 may have core areas 3&5 therein to reduce the material and weight thereof. Such areas may be omitted and the material could be removed from between the screws 2&1; Locating pins 35MB may be employed to properly align the casting portion and disks 179 and 299 when being assembled.

Referring to FIGS. 28 to 31, a reciprocating type of pump is illustrated, that wherein a housing 308 has an intake port 309 and a pressure discharge port Bill. The spill-off or by-pass port 312 is disposed on the opposite side of the housing. The housing is provided with a rotatable cylindrical element 313 containing nine cylinders 314- having therein pistons 315 which are operated in reciprocation by a driven tilted swash plate which can be angularly fixed, not herein illustrated. During a single revolutoin of the element 313, each of the nine pistons 315 will have moved to the right, as illustrated in the figure, to draw in a supply of intake fluid and will have moved to the left to exhaust the pressurized fluid in a complete reciprocating cycle thereof. Each of the cylinders 314 is joined by a passageway 316 to an aperture 317 which communicates with a reservoir 318 joined to a passageway 319 which communicates with the outlet port 311. The passageway 317 is extended to provide an aperture 32h containing a spring 321, the tension on which may be changed through the adjustment of a supporting plug 322. The springs 321 hold the balls 323 against seats 324 at the bottom of the passageways 317 with a light pressure. The halls prevent a return flow or" fluid from the pressure side of the pump.

A plate 325 is disposed at the end of the rotatable element 313 and secured in fixed position to the housing 363 by a key 326. The plate has a plurality of apertures 327 disposed angularly inward toward the center of the plate 325 from the annular intake reservoir 328. The plate also has rows of a plurality of apertures 331 which are disposed at an angle from the inner portion of the plate toward the outer periphery thereof substantially parallel to the passageways 327. With this arrangement, the apertures 327 and 331 communicate with the cylinders 314, the apertures 327 communicating with the reservoir 328 and the apertures 331 communicating with a recess 332 disposed inwardly of the reservoir 323 out of communication therewith. The recess 332 communicates through a plurality of passageways 333 and 334 with an annular passageway 335 which communicates with an annular passageway Eat in the housing 338. The passageway 336 communicates with the spill-over or by-pass port 312 to direct the by-passed fluid to tank. The recess 332 and the plurality of passageways 333 and 334 are disposed within a rotatable element 336 which is sealed to the interior of the housing by the sealing rings 337. The element 336 has a gear sector 338 on its left-hand end containing a plurality of teeth 339 which engage the teeth 222 of a cylindrical rack 223. It is to be understood that an adjustable spring may be provided between the housing 308 and therotatable element 336 to vary the pressure against which the differential cylindrical rack 223 must operate to rotate the element 33-6 and thereby change the position of the recess 332 relative to the spillover apertures 331. This controls the point at which the pressurizing of the fluid will occur within the cylinders 314 during the upstroke of the pistons 315. In this arrangement, a full discharge of fluid may be obtained from the pump or any less amount of fluid may be discharged at the normal pressure. It will be understood that the pressure may be increased within the capacity of the driving motor when a great amount otfluid has been bypassed through the by-pass port 312 so that only a small amount of fluid is being acted upon by the pistons.

It will thus be seen that whether a vane, sirocco, reciprocating or any type of pump known to be suitable is employed, means may be provided for spilling oil a part of the full intake of fluid before pressurizin g the remainder to thereby reduce the rate of delivered fluid and, if desired, to increase the pressure thereof Without any danger of heating the pump to damaging temperature. he pump is constantly maintained cool by the full intake of fluid, and by discharging an amount before pressurizing, the amount delivered is thereby controlled both as to volume and pressure within the limits of the applied energy to rotate the pump.

What is claimed is:

l. A hydraulic pump having relatively movable members for pressurizing a fluid when delivered to an increas ing volume zone and delivered from a pump outlet from a decreasing volume zone, said pump having an intake orifice through which fluid is delivered to said increasing volume zone at a constant rate, outlet means from said ecreasing volume zone to the outlet from said from which pressurized fluid is delivered, and adjustable outlet means on said members for by-passing a portion of said intake fluid from said delivery volume zone to a second outlet from said pump before the pressurizing thereof to decrease the rate of delivery of pressurized fluid from said first outlet, whereby a full flow of fluid passes through the pump at all times even though only a portion thereof is highly pressurized.

2. A hydraulic pump having relatively movable members for pressurizing a fluid when delivered to an increasing volume zone and delivered from a pump outlet from a decreasing volume zone, intake means through which fluid from the exterior of the pump is delivered to said increasing volume zone at a constant rate, outlet means from said decreasing volume zone to the outlet from said pump from which pressurized fluid is delivered, adjustable outlet means on said members for lay-passing a portion of said intake fluid from said delivery volume zone to a second outlet from said pump to prevent the pressurizing thereof through said first outlet and to decrease the rate of delivery of pressurized fluid from said first outlet, whereby a full flow of fluid passes through the pump at all times even though only a portion thereof is highly pressurized, and means for automatically increasing the flow of lay-passing fluid for reducing the rate of delivery of pressurized fluid so that the pressure thereof may be substantially raised within the permissible limits of the driving power of the pump.

3. A hydraulic pump having relatively movable members having increasing and decreasing volume zones therebetween for delivering fluid at a predetermined flow per minute from said decreasing volume zone for an applied power, said pump having two outlets, said members having intake means for supplying fluid from the exterior of the pump at a constant rate to said increasing volume Zone, outlet means from said decreasing volume zone for highly pressurized fluid to one outlet from the pump, ad justable outlet means on said member for by-passing an amount of said intake fluid from said second outlet from the pump before it is highly pressurized from said decreasing volume zone proportionate to the reduction of the delivery of the pressurized fluid from said first outlet from the pump, and means for adjusting said adjustable outlet means for by-passing an additional amount of iluid from said second outlet from the pump from the decreasing volume zone when the pressure on the highly pressurized fluid is substantially increased to reduce the volume which is delivered from said first outlet from the pump, the increase in pressure and the decrease in volume providing a ratio within the ability of the applied power to handle.

4. A hydraulic pump having two members which are rotated relative to each other to operate on fluid in increasing and decreasing volume zones therebetween, said pump having at least two outlets, one of said members having a passageway for delivering a desired amount of fluid at a predetermined pressure to said first outlet from the pump from said decreasing volume zone, and a pair of plates one at each side of said members, one of said plates having an intake passageway for the constant delivery of intake fluid to the increasing volume zone, the other of said plates having a discharge passageway through which the intake fluid may be by-passed to said second outlet from the pump from the decreasing volume zone at a rate inversely of the rate of delivery of prossurized fluid, whereby at a constant intake of fluid in the increasing volume zone only a portion thereof may be highly pressurized within the decreasing volume zone when an amount thereof is by-passed to the second outlet from the pump from the decreasing volume zone before being highly pressurized.

5. A pump having a rotor and a compression ring with increasing and decreasing volume zones therebetween, slots in the rotor, vanes in said slots engaging said compression ring, at least two outlet passageways from said pump for fluid in said rotor between said slots and out of communication therewith, plates on each side of said rotor and ring, one of said plates having .1 opening therein for the intake of fluid to said increasing volume zone, the other of said plates being adjustable angularly and having an opening therein for by-passing fluid from the decreasing volume zone through one of said outlets from the pump, the flow of said intake fluid being at a constant rate, the flow of pressurized fluid from another outlet from the pump being at the same rate when said plate having the by-pass opening is in one position, with the rate of delivery of pressurized fluid from another said outlet from the pump changing with the chan e in angular position of said last plate for by-passing from the first outlet from the pump an amount of said intake fluid from said decreasing volume zone proportionate to the amount 15 of delivered fluid which remains to be pressurized in said decreasing volume zone.

6. A pump having relatively movable members for pressurizing a fluid passing from an increasing volume zone to a decreasing volume zone, a plate having a pinrality of apertures communicating with the decreasing 'volume zone, and a second plate movable relative to said first plate and having an aperture which may uncover some or all of the apertures of said first plate, said pump structure having a bypass passageway to an outlet 'rom said pump to which fluid from said apertures in tl e first said plate is conducted to permit the remainder of the fluid in said decreasing volume zone to be pressurized and delivered from a second outlet of the pump.

7. A pump having relatively movable members for pressurizing a fluid passing from an increasing volume zone to a decreasing volume zone, a plate having a plurality of apertures communicating with the decreasing volume zone, a second plate movable relative to said first plate and having an aperture which may uncover some or all of the apertures of said first plate, said pump structure having a by-pass passageway to an outlet from said pump to which fluid from said apertures in the first said plate is conducted to permit the remainder of the fluid in said decreasing volume zone to be pressurized and delivered from a second outlet of the pump, and means for moving said second plate including piston means in communication with the pressurized fluid delivered from said decreasing volume zone for moving the piston means endwise and shifting the second plate when the pres-sure of the decreasing volume zone changes.

8. A pump having relatively movable members for pressurizing a fluid passing from an increasing volume zone to a decreasing volume zone, a plate having a plurality of apertures communicating with the decreasing volume zone, a second plate movable relative to said first plate and having an aperture which may uncover some or all of the apertures of said first plate, said pump structure having a bypass passageway to an outlet from said pump to which fluid from said apertures in the first said plate is conducted to permit the remainder of the fluid in said decreasing volume zone to be pressurized and deliv red from a second outlet of the pump, and piston means for moving said second plate disposed in communication with the pressurized fluid delivered from said decreasing volume zone moving the piston means endwise and shifting the second plate when the pressure of the decreasing volume zone changes, said piston means being removable and insertable end for end and other of said pump parts being rearrangeable to permit the pump to be rotated in the opposite direction.

9. A hydraulic pump having a housing and relatively movable members for drawing in fluid in one position of the members and for forcing the fluid from the pump in another position thereof, said housing having an inlet port, an outlet port from said pump, means within the housing associated with the members for providing an adjustable by-pass to a second outlet from said pump, said members when moved relative to each other producing a full intake of fluid through said inlet port, and means for directing some of the intake fluid into said bypass and second outlet port before it is pressurized so that only the remainder of the intake fluid will be pressurized and delivered from said first outlet port.

10. A vane type hydraulic pump having a rotor and a compression ring for pressurizing a fluid delivered to an increasing volume zone and delivered from a decreasing volume zone, a housing for said pump containing an inlet port, an outlet port from said pump, and a by-pass to a second outlet from said pump, the increasing volume zone producing a full intake of fluid through said inlet port, said decreasing volume zone pressurizing that portion of the intake fluid remaining from the unpressurized portion delivered to said by-pass and from the said second ra ar-a outlet port, and means on said rotor within the housing for regulating the flow to sai bypass.

11. A hydraulic pump for delivering a rated pressure of fluid, said pump having a housing containing an inlet port, an outlet from said pump and a bypass to a second outlet from said pump, means within the housing for drawing in a full intake of fluid through said inlet port, means within the housing for pressurizing at least some of the intake fluid and delivering it from the pump from said first outlet, and means within the housing for directing some of the intake fluid to the by-pass and from the second outlet from the pump without being pressurized to the rated pressure to thereby reduce the amount of fluid pressurized to the rated pressure which is delivered from the first said outlet while retaining the pump cool by the passage of a full intake of fluid therethrough at all times during the pump operation.

12. A pump having a housing containing an inlet port, an outlet from the pump and a by-pass to a second outlet from the pump, means within the housing for drawing in a full intake of fluid through said inlet port, means within the housing for pressurizing at least some of the intake fluid and delivering it from the first said outlet from the pump, means within the housing for directing some of the intake fluid to the bypass and from the second outlet from the pump, said directing means embodying a pair of plates one of which is angularly adjusted relative to the other, and means responsive to the pressure of the delivered fluid for angularly shifting said one plate for directing some of the fluid to said by-pass and second outlet from the pump.

13. A pump having a housing, said housing having an inlet port and two outlet ports from the pump, a rotor in said housing having a shaft portion extending from each end thereof, said rotor having substantially radially disposed slots with substantially radially disposed discharge passageways 'therebetween spaced from and out of communication with the slots, one of said shaft portions having a passageway connected to the passageways between said slots, radially movable vanes disposed in said slots, a compression ring encompassing said vanes and rotor providing an increasing volume zone and a decreasing volume zone, disks abutting opposite sides of said rotor and ring, each said disk having a passageway extending therethrough, the passageway on one of said disks being in communication with a fluid supply delivered to the increasing volume zone from said inlet port, the passageway in said other disk communicating with a discharge area in communication with the decreasing volume zone and one of said outlet ports, and means for adjusting said other disk to uncover at least a portion of said decreasing volume zone so that the fluid remaining therein will be pressurized and delivered to said other outlet port and from said pump.

14. A hydraulic pump having relatively movable pumping members which provide a maximum rate of delivery of fluid at a desired pressure for a power input, said pump having an inlet port to the pump and two outlet ports from the pump, the rate of intake of fluid to said inlet port being substantially constant, one said outlet port from the pump having an adjustable means within the housing associated with the members for by-passing a variable portion of the intake fluid before being substantially pressurized while the remaining portion is delivered from the other outlet port and from the pump after being pressurized, the reduced rate of delivery of the fluid from said other outlet port from said pump permitting the pressure thereof to be increased to such proportion as is within the permissible limits of the power input.

15. A hydraulic pump having relatively movable pumping members and a rate of delivery of fluid at a desired pressure when driven at a constant speed by a power source, said pump having an intake orifice through which fluid is delivered at a constant rate and two discharge orifices from the pump, and means within the housing associated with said members which is responsive to an increase in pressure of the delivered fluid for reducing the rate of delivery of pressurized fluid from one of the discharge orifices and raising the pressure thereof within the limits of the power source while discharging other of the intake fluid from the second said discharge orifice and from the pump without being pressurized to said raised pressure.

16. A pump having a housing, a rotor in said housing having a shaft portion extending from each end thereof, said rotor having substantially radially disposed slots with substantially radially disposed discharge passageways therebetween spaced from and out of communication with the slots, one of said shaft portions having a passageway connected to the passageways between said slots, radially movable vanes disposed in said slots, a compression ring encompassing said vanes and rotor providing an increasing volume zone and a decreasing volume zone, disks abutting the opposite sides of said rotor and ring, each said disk having diametrically disposed passageways extending therethrough, the passageways on one of said disks being in communication with a fluid supply delivered to the increasing volume zone, the passageways in said other disk communicating with a discharge area in communication with the decreasing volume zone, and means for angularly adjusting said other disk, said pump having two outlet ports leading from said housing, one communicating with the decreasing volume zone, the other communicating with said discharge area from the decreasing volume zone.

17. A pump having a body, relatively movable means within said body for pressurizing a fluid, said pump having two outlet ports for said fluid from the pump, an intake disk having an intake passageway at one side of said relatively movable means and communicating with an increasing volume zone of the pump, a discharge disk on the opposite side of said relatively movable means having a by-pass discharge passageway communicating with a decreasing Volume zone, and means for adjusting said discharge disk for discharging a desired amount of intake fluid from the decreasing volume zone and directing it from one of said outlet ports and the pump, the remaining amount of fluid being pressurized in said decreasing volume Zone and discharged from said other outlet port, said pressurized fluid at reduced volume having the pressure thereof substantially increased when resistance to the flow from said other outlet orifice is increased.

References Cited in the file of this patent UNITED STATES PATENTS Re. 23,086 Hell Feb. 22, 1949 1,036,934 Toaz Aug. 27, 1912 1,330,547 Mehlhaf Feb. 10, 1920 1,486,835 Hill Mar. 11, 1924 1,912,738 Svenson June 6, 1933 2,059,675 Woodard Nov. 3, 1936 2,117,512 Scott May 17, 1938 2,425,000 P aget Aug. 5, 1947 2,509,321 Topanelian May 30, 1950 2,565,077 Holl Aug. 21, 1951 2,570,411 Vickers Oct. 9, 1951 2,604,046 Stoyke July 22, 1952 2,651,994 De Lancey et a1 Sept. 15, 1953 2,653,549 Knight Sept. 29, 1953 2,658,344 Welch Nov. 10, 1953 2,664,047 Huber Dec. 29, 1953 2,685,842 Hufferd Aug. 10, 1954 2,688,927 Nuebling Sept. 14, 1954 2,694,288 Nubling Nov. 16, 1954 2,696,170 Hill Dec. 7, 1954 2,728,297 Cilley Dec. 27, 1955 2,768,582 Klessig et al Oct. 30, 1956 2,790,391 Holl Apr. 30, 1957 2,887,060 Adams et a1 May 19, 1959 2,898,862 Brundage Aug. 11, 1959 2,899,903 Ryder Aug. 18, 1959 2,924,182 Blasutta et a1 Feb. 9, 1960 2,937,599 Rosaen May 24, 1960 2,941,475 Blair June 21, 1960 FOREIGN PATENTS 220,503 Australia. Mar. 2, 1959 1,035,238 France Apr. 15, 1953 1,149,700 France July 22, 1957 415,425 Germany June 19, 1925 843,766 Germany July 14, 1952 1,024,196 Germany Feb. 13, 1958 316,670 Great Britain Printed 1931 811,557 Great Britain Apr. 8, 1959 521,512 Italy Mar. 29, 1955 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No, 3, 120,814 February 11 1964 Otto Mueller It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 2, line 8 for "man" read main column 1 1 line .21 for "member" read members column 15, line 46 before "moving" insert for Signed and sealed this 23rd day of June 19640 (SEAL) Attest:

ERNEST W; SWIDER EDWARD J. BRENNER Asiesiing Officer Commissioner of Patents 

1. A HYDRAULIC PUMP HAVING RELATIVELY MOVABLE MEMBERS FOR PRESSURIZING A FLUID WHEN DELIVERED TO AN INCREASING VOLUME ZONE AND DELIVERED FROM A PUMP OUTLET FROM A DECREASING VOLUME ZONE, SAID PUMP HAVING AN INTAKE ORIFICE THROUGH WHICH FLUID IS DELIVERED TO SAID INCREASING VOLUME ZONE AT A CONSTANT RATE, OUTLET MEANS FROM SAID DECREASING VOLUME ZONE TO THE OUTLET FROM SAID PUMP FROM WHICH PRESSURIZED FLUID IS DELIVERED, AND ADJUSTABLE OUTLET MEANS ON SAID MEMBERS FOR BY-PASSING A PORTION OF SAID INTAKE FLUID FROM SAID DELIVERY VOLUME ZONE TO A SECOND OUTLET FROM SAID PUMP BEFORE THE PRESSURIZING THEREOF TO DECREASE THE RATE OF DELIVERY OF PRESSURIZED FLUID FROM SAID FIRST OUTLET, WHEREBY A FULL FLOW OF FLUID PASSES THROUGH THE PUMP AT ALL TIMES EVEN THOUGH ONLY A PORTION THEREOF IS HIGHLY PRESSURIZED. 